Microsoft details global police data requests
More than 75,000 requests were made by police forces around the world for data on Microsoft users in 2012.
The figures were revealed in Microsoft's first transparency report which detailed how often police forces sought data to aid investigations.
US police forces topped the list of agencies keen to know who created specific images or other content.
In most cases, Microsoft only handed over basic information such as login names and IP addresses.
The transparency report from Microsoft follows similar efforts by Google, Twitter and others to let users know who is seeking data about what people do online.
The requests covered more than 137,000 accounts on Microsoft's many services including Hotmail, Outlook.com, Xbox Live, Skype and others. It was hard to estimate how many individual users that involved, said Brad Smith, Microsoft's general counsel, in a blogpost, because many people ran lots of separate accounts.
Only 2.1% of the requests involved Microsoft handing over the content people created. This includes documents or images stored on servers or sent via email as well as copies of messages sent through its services. More than 99% of requests for content data came from US law enforcement agencies.
Most of the other requests were for non-content data such as login names, IP addresses or other low-level identifiers. Police forces in five countries - the US, UK, Turkey, Germany and France - made the bulk of these requests.
Finally, about 18% of requests involved Microsoft handing over no data at all, said the report, either because there was no data to be found or the request was not submitted properly.
"While law enforcement requests for information unquestionably are important... only a tiny percentage of users are potentially affected by them," wrote Mr Smith. He estimated that only 0.02% of its users felt the effect of a police request for data.
Microsoft said it would update the report every six months.